The purpose of this project is to characterize the genetic basis of the sensory controls of alcohol consumption. There is clear evidence that the predisposition to ingest alcohol involves differences in the way alcohol is perceived, but the relative importance of the various facets of alcohol perception in the control of alcohol intake is unknown. Based on findings that the C57BL/6ByJ and 129/J strains of mice differ markedly in alcohol and sucrose intake, this project will make use of these animals to characterize the attributes of alcohol that influence its attractiveness, and determine the genetic loci for these differences using QTL mapping of F3 hybrid. To characterize alcohol-related ingestive behavior in C57BL/6ByJ and 129/J mice strains, groups of mice will receive to drink solutions having a sweet taste, bitter taste, orosensory irritation, or caloric value. Long-term (48-h) two-bottle free-choice tests and brief-exposure tests will be used to determine intake. The results of these experiments will tell us which sensory facets of alcohol are perceived differently by the B6 and 129 strains, and will be used to form a battery of tests for analysis of solution acceptance by approximately 500 male and 500 female F2 hybrids of the C57BL/6ByJB6 and 129J strains. Correlations between consumption of these solutions by the F2 generations will be determined, and the relative contribution of the various sensory components of alcohol to alcohol intake will be estimated. QTL mapping will identify the loci involved in alcohol consumption, and show which specific components of this behavior they determine. These studies will identify genes involved in determining various facets of the behavioral response to alcohol ingestion. Such studies will pave the way for an examination of the role of genetically-mediated sensory factors in human alcohol intake and alcoholism.